9 Respuestas

I switched out the hard drive on a 27" 2011 today and I can confirm that the hard drive sensor that attached to the drive is gone. I put in a Seagate 1 TB SSHD and it's running just fine. No modifications were needed.

@mayer - The first ones had the needed firmware. But, I guess Apple got PO'd and had Seagate pull the magic fix. Now you need the OWC in-line sensor. Besides, if you use any other HDD or SSD you'll need it.

@mayer and @danj Im planning to use startech dual bay 2.5-3.5 hdd adapter and put two ssd in it. If I don't need the OWC heat sensor that would be great but if I do where to I put it? Can I just attached it to the grill of the adapter? What is the correct way to do it just incase my imac does not develope to fan issue do I still add the sensor? My iMac is 27" 2.7GHz i5 mid 2011. Thanks

The OWC report is quite inaccurate and I wish they did some more testing or at least read the forums before creating mass panic.

The SATA data connectors are very standard and so is the SATA power cable feeding the hard drive. The only difference is that they used 7 wires instead of 5, probably some extra grounds.

I installed a Vertex3 SSD and used a plain 4 wire Y-splitter sata power cable which effectively discards the 3.3V from the apple's wiring and only feeds 5V and 12V to the original drive. Guess what, fan speed is as quiet as it can get and the Apple Hardware Test passes successfully.

I went further and moved the internal HDD from SATA0 to SATA1 port to better accommodate the SATA connector for the SSD and this didn't create any adverse effects.

Another member of the forum swapped the 1TB WD Black with a 2TB WD Black and again, no adverse effect, Hardware Test completed successfully.

With the SSD in place now, the only thing I can hear is my breath reflected by the glass screen

The KISS principle in play and offers an excellent solution. It worked for me Poon. Thank you. Now, if I can only figure out where to hide that darn splitter cable safely. It looks so out of place inside the iMac. :)

It may be a little late but thanks for this tip! I just installed a WD 5TB Black and Samsung 850 250 GB SSD in my mid 2011 27" iMac and I didn't have to buy adapters or funny cables! I used the SATA Power splitter suggestion on the spinner power cable and a normal SATA cable from the MoBo connector to the SSD and mounted it all under the Optical drive. For the price of $10 for 2 cables my iMac is now a killer and has SILENT FANS !! You are a genius.

I have tried this solution and confirm, that it works perfectly. I put an SSD, instead of preinstalled by Apple HDD and the system kernel task doesn't take 300% of the CPU, and the Apple hardware test passes successfully.

As Timothy suggested I have used the Y-SATA Power supply splitter. In order for it to fit in Apple's default SATA Data+Power cable I cut the holding sides of the Father's plug of the cable I had bough. Then I disassembled the iMac till the motherboard following this guide: iMac Intel 27" Retina 5K Display SATA Cable Replacement . And replaced the SATA data cable with the one I also had bought.

I am confident that the temperature sensor is one different to the S.M.A.R.T sensor fitted in all drives.

When you replace the HDD with a non-standard HDD (ie. not one that Apple have baptised and granted permission to live inside their oh so superior machine *NOT*), the iMac doesn't use the S.M.A.R.T data, and as such reports that there IS no sensor, or atleast that it's broken, so it kicks up the fans just in case the HDD has caught fire or has been blasted into the centre of the sun... Y'know... Just in case.

The solution to this is to effectively short the connector out. This allows for a current to flow and for the iMac to be of the impression that the temperature sensor is working and at optimum temperature.

Another POTENTIAL solution that I've yet to try is to buy a temperature sensor belonging to the OPTICAL drive. It shares the same connectors as the previous HDD sensor, and it performs the same task, so I can't see it failing. However, these are difficult to source and can be a little costly, so if I take that route, I'll update...

There's also a piece of software called HDD Fan Control or similar. I wouldn't bother though - It didn't help me very much.

Update

Here is my update - Worked a treat.

So don't panic! You can choose any HDD you like - Use the old-fashioned method of sticking a temperature sensor to it from an old optical drive. Works brilliantly.

Part No. 922-8222 I think... Image here: http://www.powerbookmedic.com/xcart1/ima... When you open the machine, I believe the temperature sensor cable is attached to the logic board using small two/three-pin cable. If you can find any temperature sensor that fits in that slot, you're fine.

Question to oldturkey. on his update. Where did you insert the temp sensor cable? If the existing one is the wider 7-wire connector, where did you put the "old-fashioned" optical drive sensor, which is strictly 2-wire. The only way i can see you do that is by not having one on the optical drive at all.

It should be noted here that on the SATA side of the cable the wires 1 and 4 have to be shorted (and NOT wire 2 and 7). This is much easier then Apple's official solution where you have to take the iMac almost completely apart.

For better understanding I have added below some (low resolution) photos. (Sorry for the bad quality).

CAUTION!!! This modification is ONLY VALID when you switch to a solid-state drive (SSD).

DO NOT use this mod to connect a normal harddisk drive! This will most likely result in massive overheat of your iMac.

Well, also Apple has used this solution on their "SSD only" 2011 iMacs! So it is fully "Apple approved". ;) The only difference is that Apple is shorting wires 2 & 7 on the PCB side of the SATA cable. This mod here works as it should; the fans are no longer running at maximal speed. But yes, if you have the time and the chance then it is better to order the OWC adapter. That will be then a perfect and "clean" solution.

Well ... I wouldn't agree Apple supports your direction. Yes, electrically it will work but you are taking the long route. I would use the jumper block Apple offers as a spare if I was doing a SSD only setup. The OWC sensor is still the better solution as you don't need to pop the logic board forward to put in on.

You don't need the OWC sensor in a 2012 iMac. Apple has a non-standard power connector and this causes the voltage to go awry and cause the fans to run at full speed. What you need to do is get one of those SATA power "Y" splitters and plug your Mac power cord into that and the IMac won't spin up the fans full speed. You will also have to lift the motherboard and plug in a standard SATA data cable into the spare connection on the motherboard. If you do this you're only expense will be the power "Y" splitter and the SATA cable. I've done exactly this on several 2011 iMacs and kept the internal CD-ROM to boot. It will also pass the Apple Hardware Test. ;)

Can you please explain if it is possible to switch HDD (not SSD) on an iMac 27" late 2012 for a Seagate Barracuda ST2000DM006 64MB 2TB with your trick without the fan problem? I swapped the original 1 TB HDD for this new one but my fan is spinning if I'm not using Macs Fan Control. I don't understand your explanation with the Y splitter and Mac Power Cord (what has it to do with it?). Thanks in advance

I just installed a 480GB SanDisk "SSD Plus" in a mid-2011 iMac (with no external thermal sensor on the old drive). I've booted from an El Capitan installer flash drive, formatted the SSD, and am installing El Cap as I write this. No fan noise at all so far. I'm hesitant to clip wires on the power cable, so I'm really hoping my luck holds!

If the fans start roaring when booted from the new SSD/El Cap, then I guess I'll have to try P J Sch's technique...

The weird thing is that I feel like I've swapped drives in other 2011 iMacs (possibly early-2011?) that still used the sensor cable, and therefore require the OWC part that Dan keeps recommending above. I have, and was prepared to use, that part, but there's no place to plug it in on this model!

The machine I upgraded worked fine, without any fan noise. I think your "mileage may vary", but if you open yours up, pull the stock drive, and there is no little cable wired to the jumpers on the drive, you should be okay without the OWC part.

I changed out the stock Barracuda 1GB drive after failure using a new 4TB Seagate drive with a 256MB cache. The fan was maxed out once I replaced the drive. I use a software solution, namely TG Pro, that allows the User to control the fan speed. The app also monitors numerous temperatures. Works like a charm.

Hello from Norway! I have bought a mid 2011 27" iMac where it have been innstalled a 1TB SSD together with a 3TB HDD. It is also a Mac FanControll installed. But it is the same problem with black screen on this machine. Some times I have ti restart and some times the screen have to be black before i Can log in. I am looking for a solution om this problem?